1. Field of the Invention
The present disclosure relates to a vacuum cleaner. More particularly, the present disclosure relates to a cyclone dust collecting apparatus separating and collecting dust and dirt using centrifugal force.
2. Description of the Related Art
Generally, a vacuum cleaner generates suction force using a motor so as to draw-in air containing dust, dirt and so on (hereinafter, referred to as dust-laden air) from a surface to be cleaned by the suction force. Dust, dirt and so on (hereinafter, referred to as dust) contained in the dust-laden air is separated from the dust-laden air when the dust-laden air passes through a dust collecting apparatus disposed in a cleaner body of the vacuum cleaner, and cleaned air is discharged outside the cleaner body.
Recently, cyclone dust collecting apparatuses have been widely used as a dust collecting apparatus that separates dust from dust-laden air and collects the separated dust. The cyclone dust collecting apparatuses separate dust from dust-laden air using centrifugal force.
The conventional cyclone dust collecting apparatus includes an air suction pipe drawing-in dust-laden air, a cyclone body forcing the drawn-in dust-laden air to whirl, and an air discharging pipe discharging air having dust separated.
Therefore, the dust-laden air drawn in through the air suction pipe by suction force forms a whirling air current inside the cyclone body. Then, dust is separated and collected by the centrifugal force caused by the whirling air current, and cleaned air is discharged through the air discharging pipe.
The conventional cyclone dust collecting apparatus can easily separate relatively heavy dust from the drawn-in dust-laden air because there is a great difference between the centrifugal forces operating upon each of the relatively heavy dust and the air. However, the conventional cyclone dust collecting apparatus cannot separate fine dust well from the dust-laden air because there is little difference between weights of the fine dust and the air.
To increase the fine dust collecting efficiency, U.S. Pat. Nos. 4,643,748, 4,826,515, and 4,853,008 disclose a multi-cyclone dust collecting apparatus that has two cyclones and forces dust-laden air to whirl in two steps.
Because the conventional multi-cyclone dust collecting apparatus forces the dust-laden air to whirl in two steps, it has a higher fine dust collecting efficiency than the cyclone dust collecting apparatus having one cyclone. However, the conventional multi-cyclone dust collecting apparatus has a problem that a great pressure loss occurs when the dust-laden air is drawn-in from an inner cyclone to an outer cyclone.